The "cold full moon" will be the biggest and brightest moonrise of the year.
The only supermoon of the year is on the horizon as 2017 comes to a close. The celestial event will be visible to the naked eye and therefore witnessed by countless stargazers. But what exactly is a supermoon, and when is the best time to see it? Travel + Leisure has got you covered.
What is a supermoon?
A supermoon is a full moon that appears bigger and brighter than normal because of its increased proximity to the Earth. This happens when the moon’s fluctuating orbit is at the shortest distance from the planet, while the alignment between the Earth, moon and sun creates a full moon at the same time. The brightness of the full moon in all its glory, combined with the reduced distance from Earth, creates the supermoon effect visible to us Earthlings below.
Supermoons technically happened about four to six times a year on average, but we don’t see most of them because the phenomenon also happens during an invisible new moon. The last full moon supermoon occurred more than a year ago, so astronomy aficionados should pounce on the opportunity now.
You may have also heard the upcoming supermoon referred to as a “cold moon.” Don’t worry — that’s not a separate celestial event you’ll need to look out for — it’s just the name of a full moon that occurs in December, hence the “cold” description.
When is the supermoon?
This year’s supermoon will be visible on Sunday, Dec. 3. The moon will become completely full at 10:47 a.m. E.T., but you’ll have to wait until moonrise to truly experience the sight. In the U.S., that will occur sometime around 5 p.m. local time and last throughout the night.
How to photograph the supermoon
Casual smartphone photographers should make sure they have their phones stabilized on a firm surface like a ledge or, ideally, tripod.
“Tap the screen and hold your finger on the object [in this case, the moon] to lock the focus,” NASA photographer Bill Ingalls said. “Then slide your finger up or down to darken or lighten the exposure.”
DSLR photographers should use the daylight white balance for capturing the supermoon’s glow, Ingalls said. Longer telephoto lenses are ideal, but keep in mind: “[T]he moon is a moving object. It’s a balancing act between trying to get the right exposure and realizing that the shutter speed typically needs to be a lot faster.”